There has been a well-known safety barrel theory in the field of information security saying that “Don't let your safety barrel leak at the bottom”. If firewalls, intrusion detection, VPN, security gateways form the wall of the safety barrel, then identity authentication is the barrel bottom. For the past few years, with the fast development of both identity authentication theory and the technology, there have been biometric identification technologies such as retina recognition, iris recognition, and fingerprint recognition, to sum up, identity authentication system through the following methods to completes the certification process. (1) “what you know”—authenticating your identity based on the information you know; (2)“what you have”—authenticating your identity based on the things you have; (3)“who you are”—authenticating your identity based on your unique body characteristics; (4) two-factor-authentication—i.e. the combination two of the three methods above.
Nevertheless, the above-mentioned authentication methods and systems face great risks and challenges, all of the above methods have been cracked in the following examples.